Synthesis 2022; 54(07): 1833-1842
DOI: 10.1055/a-1644-2930
paper

Oxalylacetylenes as Dielectrophiles for Annulation of Quinoline Rings: Synthesis of Highly Functionalized 1,3-Oxazinoquinolines

Kseniya V. Belyaeva
,
Lina P. Nikitina
,
Veronika S. Gen’
,
Andrei V. Afonin
,
Boris A. Trofimov
This work has been approved by plans for research projects at the IPC Russian Academy of Sciences (State Registration No. AAAA-A16-116112510005-7).


Abstract

Oxalylacetylenes act as dielectrophiles in the annulation of quinolines to give highly functionalized 1,3-oxazine cycles decorated with ethynyl, oxalyl, ester and aryl substituents. The annulation proceeds under mild conditions (room temperature, without catalyst) in 2:1 mode with respect to acetylene and quinoline to deliver 1,3-oxazinoquinolines in 45–88% yields. A beneficial feature of the reaction is that, in contrast to results on the reaction of quinolines with trifluoroacetylacetylenes in the presence of water, where H2O acted as a third electrophile, leading to the 1,3-oxazinoquinolines containing a hydroxyl group, this reaction well tolerates the aqueous medium. This reaction also tolerates isoquinoline and phenanthridine.

Supporting Information



Publication History

Received: 02 August 2021

Accepted after revision: 14 September 2021

Accepted Manuscript online:
14 September 2021

Article published online:
21 October 2021

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